Great efficiency from the rook. Having done its job on the g8, it's time to go back to an open file.
14. f3d2 The bishop is stuck on c2, but Ding had foreseen this. 14... h8g8 The only way to justify 13...Nbd7. Black is right in time to save the bishop. The idea is to play …g6-g5 and bring it back. 15. g4g5 This grants the bishop the f5-square. 15... f6h5  16. f4h2 White's plan is to play f3-e4.